• Restorative Dentistry and Endodontics
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• v.35 no.6
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• pp.486-491
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• 2010

Objectives: This study examined the effect of 2% chlorhexidine on the ${\mu}TBS$ of a direct composite restoration using one-step self-etch adhesives on human dentin. Materials and Methods: Twenty-four extracted permanent molars were used. The teeth were assigned randomly to six groups (n = 10), according to the adhesive system and application of chlorhexidine. With or without the application of chlorhexidine, each adhesive system was applied to the dentin surface. After the bonding procedure, light-cure composite resin buildups were produced. The restored teeth were stored in distilled water at room temperature for 24 hours, and then cut and glued to the jig of the microtensile testing machine. A tensile load was applied until the specimen failed. The failure mode was examined using an operating microscope. The data was analyzed statistically using one-way ANOVA, Student's t-test (p < 0.05) and Scheffet's test. Results: Regardless of the application of chlorhexidine, the Clearfil $S^3$ Bond showed the highest ${\mu}TBS$, followed by G-Bond and Xeno V. Adhesive failure was the main failure mode of the dentin bonding agents tested with some samples showing cohesive failure. Conclusions: The application of 2% chlorhexidine did not affect the ${\mu}TBS$ of the resin composite to the dentin using a one-step self-etch adhesive.

• Journal of the Korean Chemical Society
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• v.36 no.4
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• pp.552-557
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• 1992

Chloramphenicol was studied by differential pulse polarography (DDP). A reduction peak which is dependent on pH of the solution appeared in the voltage range between zero and -1.50 volt vs. Ag/AgCl (sat. KCl) reference electrode. A plot of peak potentials (Ep) measured at room temperature (20$^{\circ}C$) vs. pH of the chloramphenicol solutions showed linear relationship changing slope (Ep/pH) at pH 8.9. The slope was -59.7 mV/pH in pH 2.7∼8.9 and -24.3 mV/pH in pH 8.9∼11.2, respectively. A log plot of peak currents (ip) vs. concentrations showed a linearity at the concentrations between 4.8 ${\times}$ 10$^{-7}$ M and 6.2 ${\times}$ 10$^{-5}$ M (0.16 ppm∼20 ppm) chloramphenicol in pH 8.0 ammonium buffer. Between the DPP method and the reference method measuring absorbance at 278 nm, the correlation coefficient was 0.996, which means an excellent linearity. The DPP method was able to detect degradation products of chloramphenicol in mild alkaline solution (pH = 8.0) more distinctly than the spectrophotometric method.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.3
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• pp.217-221
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• 1986

A column test was conducted to find out the effect of application of slaked lime, calcium sulfate, calcium superphosphate, and phosphoric acid on the solubility of lead in soil. The soil was adjusted to 310.8 ppm concentration of Pb and applied with amounts of calcium equivalent to 600, 1000, 2000 ppm as slaked lime; sulfate 144, 288, 432 ppm as calcium sulfate; phosphate 95, 190, 285 ppm as calcium superphosphate and phosphoric acid, respectively. The results obtained are as follows: 1. The increasing application of improvement agents reduced the amounts of water soluble Pb in soil. Phosphoric acid was the most effect among to the treatments. 2. The slaked lime treatment has the highest pH of soil and the lowest at the phosphoric acid one. The soil Eh has a reverse tendency the soil pH. 3. Water soluble Ca, $PO_4$ and $SO_4$ contents increased with increasing application amounts of improvement agents in soil. 4. $1N-NH_4$ OAC soluble Pb content in soil was a decreasing tendency in the order of calcium superphosphate, phosphoric acid, slaked lime, calcium sulfate and control after experiment.

• The Journal of the Korea Contents Association
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• v.19 no.3
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• pp.510-519
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• 2019

The purpose of this study was to analyze the nutrition labeling of Guk, Tang, Jjigae HMR products to provide consumers with appropriate information when selecting products, and to provide basic data on the national policies. In this study, nutritional labels of 176 products were analyzed with 57 Guk, 75 Tang, 44 Jjigae. In the menu frequency of products, Guk has the products of the specific purposes, Tang has animal protein product, Jjigae has popular products. As a result of comparing the portion size and 9 major nutrients of the product, the average sodium content of Guk was 1558.5 mg, Tang was 1472.3mg, Jjigae was 2118.0mg. By the storage temperature, the average sodium content of HMR product was 2022.9mg in freezing(below $-18^{\circ}C$), 1676.7mg in cold($-2{\sim}10^{\circ}C$), and 1250.9mg in room temperature($1{\sim}35^{\circ}C$). Therefore, it is necessary to focus on the sodium content of Frozen products in the attempt of reducing sodium in HMR products.

• The Journal of the Convergence on Culture Technology
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• v.9 no.1
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• pp.725-733
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• 2023

The evaluation of functional active ingredients and dyeing effect on cotton fabric using 16 types of natural products water extracts and 50% ethanol extracts, there were differences in color intensity, but 6 types of red, 5 types of yellow, 2 types of orange, and 3 types of green were observed. In general, the color of the 50% ethanol extract was high and clear. As a result of dyeing by immersing cotton gauze in water extracts and 50% ethanol extracts of these natural products for 2 days, the dyeing effect was generally good, and it was observed that there was little fading decrease in color even after drying at room temperature and opening and storing. The pH of the water extracts of 16 natural products ranged from neutral to slightly acidic, with no side effects on the skin. For DPPH free radical inhibition antioxidant effect, the effect of 50% ethanol extract for each sample was better than that of water extract. As for the polyphenol content, the content of the 50% ethanol extract tended to be higher than that of the water extract. Therefore, the purpose of this study was to investigate the correlation between the antioxidant activity of 16 natural extracts and the prevention of female vaginitis.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2023.04a
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• pp.49-49
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• 2023

본 실험은 콤부차의 발효시 에너지원으로 첨가되는 당(sucrose) 대신 꾸지뽕(Cudrania tricuspidata Bureau; silkworm thorn) 과일 발효액을 첨가하여 꾸지뽕-콤부차의 기능성을 구명하고자 하였다. 대조구인 콤부차는 끓여서 식힌 물 900mL에 홍차 2.4g을 넣어 한시간 동안 추출한 후 초기당도가 10°Bx가 되도록 sucrose를 첨가하였고, 처리구는 sucrose대신 꾸지뽕 과일 무게 대 sucrose의 비율을 1 대 0.9의 비율로 조제하여 발효시킨 꾸지뽕 발효액(당도 50°Bx)을 10°Bx가 되도록 희석하여 첨가하였다. 여기에 발효균인 SCOBY를 첨가한 후 실온에 3주간 보관하면서 1주일 간격으로 시료를 채취하여 총폴리페놀성 화합물 및 카테킨류 함량, 항산화 활성 및 인체 정상 폐세포주인 MRC-5와 폐암세포주인 A549의 세포 증식에 미치는 영향을 구명하였다. 발효 3주 동안 채취한 꾸지뽕-콤부차를 MRC-5 세포에 처리하였을 때 발효 2주까지는 꾸지뽕-콤부차가 대조구에 비해 약 10~30% 세포 증식효과를 보였고 발표 3주째에는 유사한 증식효과를 보였다. 폐암세포주 A549에 처리시에는 발효 2주째 대조구에 비해 낮은 증식율을 보였으나 그 차이는 크지 않았다. 이 결과는 꾸지뽕-콤부차가 인체 폐세포 증식을 촉진하나 폐암세포의 증식을 크게 억제하지는 않음을 의미한다. 총폴리페놀성화합물 함량은 대조구의 경우 발효기간이 경과함에 따라 증가하는 반면 꾸지뽕-콤부차는 조제직후 대조구에 비해 유의적으로 높은 함량을 보이다 서서히 감소하였는데 발효 2주째 대조구와 유사한 수준에 도달하였으며 3주째에는 대조구에 비해 낮은 함량을 보였다. 카테킨류(Epigallocatechin, Epigallocatechin gallate, 그리고 Epicatechin gallate, epicatechin)는 총 페놀성화합물과는 반대의 경향을 보였는데, 발표 2주까지는 꾸지뽕-콤부차의 함량이 유의적으로 높았다가 발표 3주째 크게 낮아졌다. 활성산소 제거능은 발효 2주째까지는 대조구에 비해 낮았으나 3주째 유의적으로 높아져 꾸지뽕-콤부차의 항산화활성은 카테킨류 함량에 비례함을 알 수 있었다. 기능성분 함량과 MRC-5 증식에 관한 상관분석시 총풀리페놀함량이 세포증식에 정의 상관관계를 나타내었다.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2021.04a
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• pp.28-29
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• 2021

애기똥풀(Chelidonium majus L. subsp. asiaticum H.Hara)의 지상부는 백굴채라고 불리며 항암, 항균 등의 효능을 가지고 있어 예로부터 약용으로 이용되었다. 그러나 천연 약용소재로 개발가치가 높음에도 불구하고 실생묘의 대량 확보를 위한 종자번식 관련 연구가 전무한 실정이다. 본 연구에서는 애기똥풀의 발아 및 휴면 특성을 분석함으로써 추후 종자번식을 위한 기초자료를 제공하기 위해 수행되었다. 실험재료로 사용된 애기똥풀 종자는 2019년 6월 경상북도 봉화군에서 채종하였으며 정선 후 건조상태로 실온(25℃)에 보관하였다. 종자의 1000립중은 0.57±0.01g이며, 배종비는 0.21±0.12로 조사되어 형태적으로 미성숙한 배를 가지고 있다. 종자의 활력은 테트라졸륨 검정을 통해 79%로 확인되었다. 종자의 기본 함수율은 7.64±0.25%였으며, 침지 2일 차에 최대함수율(32.6±0.34%)에 도달하였다. 초기 발아검정은 25/15℃ (light/dark, 16/8h)챔버에서 명조건과 암조건으로 구분하여 30일간 진행하였으며, 암조건은 알루미늄 호일로 광을 완전히 차단하고 최종 발아율만 조사하였다. 발아율을 조사한 결과, 명조건은 0.75±0.80%, 암조건은 5.50±1.55%로 조사되어 형태적인 휴면과 생리적인 휴면을 모두 갖는 것으로 판단하였다. 애기똥풀의 생태적인 환경을 고려하여 12주의 Summer temperature(S12, 25/15℃, 16/8h)로 층적하고 연속하여 Autumn temperature(A, 15/10℃, 16/8h)를 4주(A4)와 8주(A8)로 달리하여 종자의 휴면타파를 유도하였다. 층적 후 발아율은 모두 증가되었으며, S12-A4(54%)는 S12-A8(24.5%)에 비해서 휴면타파에 효과적이었다. 휴면타파 효과의 증진을 위해 층적처리한 종자를 500ppm의 GA₃와 GA₄₊₇에 각 24시간동안 4℃에서 침지시킨 뒤 동일한 조건에 파종하였다. GA₃가 처리된 S12-A4는 발아율이 82.0%, S12-A8는 30.8%로 유의적으로 증가하였으나 GA₄₊₇ 처리는 S12-A4(48.5%)와 S12-A8(21.3%)에서 발아율 향상 효과가 없었다. 결론적으로 애기똥풀의 휴면타파를 위해서 12주의 Summer temperature와 4주의 Autumn temperature 변온층적과 추가 GA₃ 처리가 휴면타파를 위한 효과적인 처리방법으로 판단된다.

• Restorative Dentistry and Endodontics
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• v.32 no.5
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• pp.469-475
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• 2007

The purpose of this study was to evaluate the effect of a new resin monomer on the microleakage of composite resin restorations. By adding new methoxylated Bis-GMA (Bis-M-GMA, 2,2-bis[4-(2-methoxy-3-methacryloyloxy propoxy) phenyl] propane) having low viscosity, the content of TEGDMA which has adverse effects on polymerization shrinkage might be decreased. As a result, microleakage might be improved. $2\;mm\;{\times}\;2\;mm\;{\times}\;2\;mm$ cavities with occlusal margins in enamel and gingival margins in dentin were prepared on buccal and lingual surfaces of 40 extracted human premolars. Prepared teeth were randomly divided into four groups and restored with Clearfil SE bond (Kuraray, Japan) and one of experimental composite resins; EX1, Experimental composite resin1 (Bis-M-GMA/TEGDMA = 95/5 wt%, 40 mm nanofillers); EX2, Experimental composite resin2 (Bis-M-GMA/TEGDMA = 95/5 wt%, 20 mm nanofillers); EX3, Experimental composite resin3 (Bis-GMA/TEGDMA = 70/30 wt%, 40 nm nanofillers); and Filtek Z250 (3M ESPE, USA) was filed as a control group. The restored teeth were thermocycled, and immersed in 2% methylene blue solution for 24 hours. The teeth were sectioned buccolingually with a low speed diamond saw and evaluated for microleakage under stereomicroscope. The data were statistically analyzed by Pearson Chi-Square test and Fisher Exact test (p = 0.05). The microleakage scores seen at the enamel margin were significantly lower than those of dentin margin (p = 0.007). There were no significant differences among the composite resins in the microleakage scores within each margin (p > 0.05). Bis-M-GMA, a new resin monomer having low viscosity, might in part replace high viscous Bis-CMA and might improve the quality of composite resin.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.4
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• pp.747-759
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• 2001

The sanitary status of 264 restaurants was investigated to develop a program of sanitary education at restaurants for improving sanitary levels of restaurant and consumers’ food safety. This investigation was performed through direct interviews on general items and sanitations for employees, facilities, equipments and food treatment. The restaurants are grouped into four different types according to the food served: Korean style food, Japanese style raw fish, roasted ribs, and western style food. It is found that sanitary education for employees are conducted at 66.5% of the total restaurants. The highest percentages are obtained by Korean style food restaurants (83.1%) and the lowest by western style food restaurants (55.6%).Washing facilities for employees are equipped at only 66.8% of the total restaurants. In the personal sanitation, 96.6% of the employees wash their hand after touching a dirty stuff, 77.5% after touching money and 57.1% after using telephone. It is also revealed that during food preparation shoes, overgarments, and caps are worn by 58.5%, 55.5%, and 20.6% of the employees, respectively. 73.5% of the restaurants are equipped with dish storages facilities while only 59.2% of restaurants have sterilizers for dishes. Also, chopping boards are sterilized more than once a week by 74.8% of them and knives everyday by 71.6%, 15.4% of restaurants sterilize their knives only once a week. 56.8% of restaurants check temperatures of the refrigerators and 26.2% of restaurants do not even sterilize the refrigerators. 31.8% of restaurants sterilize the kitchens with sodium hopochlorite after cooking. 93.3% of the restaurants store the raw food and the cooked foods separately. 49.8% of the restaurants refroze thawed food and 19.4% of the restaurants reuse leftovers. The frozen foods are thawed at room temperature by 49.4% of the total restaurants and 66.7% of the roasted rib restaurants.

• Journal of Food Hygiene and Safety
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• v.24 no.1
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• pp.1-11
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• 2009

Consumers are very concerned about food safety as the risk with food increased. This study was conducted to evaluate the perceptions and practices of consumers on food safety in order to collect some information for the development of consumer education program. Total 500 consumers were asked to answer for survey constituted with 6 questions of generic information, 4 of food safety perceptions and 8 of food safety practices from June to July, 2006. More than half of respondents (51.8%) were unsatisfied with the food safety management of government while the individual practices on food safety were satisfactory. Especially, most respondents (98.7%) checked the expiration date of food when they purchased and 97% of respondents were washed hands before food preparation. The higher food safety perception, the better food safety practices of consumers. These results suggest that the systematic and continuous educations on food safety hazards and the principles of sanitation management are necessary for safe food handling and perception on food safety.